From 5434da4ddff396aadf5e1098065069ea58134e26 Mon Sep 17 00:00:00 2001 From: Dong Jia Shi Date: Fri, 17 Mar 2017 04:17:28 +0100 Subject: s390: cio: introduce cio_cancel_halt_clear For future code reuse purpose, this decouples the cio code with the ccw device specific parts from ccw_device_cancel_halt_clear, and makes a new common I/O interface named cio_cancel_halt_clear. Reviewed-by: Pierre Morel Signed-off-by: Dong Jia Shi Cc: Sebastian Ott Cc: Peter Oberparleiter Acked-by: Sebastian Ott Message-Id: <20170317031743.40128-2-bjsdjshi@linux.vnet.ibm.com> [CH: Fix typo] Signed-off-by: Cornelia Huck --- drivers/s390/cio/cio.c | 59 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 59 insertions(+) (limited to 'drivers/s390/cio/cio.c') diff --git a/drivers/s390/cio/cio.c b/drivers/s390/cio/cio.c index 1b350665c823..c7ee3e44f162 100644 --- a/drivers/s390/cio/cio.c +++ b/drivers/s390/cio/cio.c @@ -309,6 +309,65 @@ cio_cancel (struct subchannel *sch) } } +/** + * cio_cancel_halt_clear - Cancel running I/O by performing cancel, halt + * and clear ordinally if subchannel is valid. + * @sch: subchannel on which to perform the cancel_halt_clear operation + * @iretry: the number of the times remained to retry the next operation + * + * This should be called repeatedly since halt/clear are asynchronous + * operations. We do one try with cio_cancel, three tries with cio_halt, + * 255 tries with cio_clear. The caller should initialize @iretry with + * the value 255 for its first call to this, and keep using the same + * @iretry in the subsequent calls until it gets a non -EBUSY return. + * + * Returns 0 if device now idle, -ENODEV for device not operational, + * -EBUSY if an interrupt is expected (either from halt/clear or from a + * status pending), and -EIO if out of retries. + */ +int cio_cancel_halt_clear(struct subchannel *sch, int *iretry) +{ + int ret; + + if (cio_update_schib(sch)) + return -ENODEV; + if (!sch->schib.pmcw.ena) + /* Not operational -> done. */ + return 0; + /* Stage 1: cancel io. */ + if (!(scsw_actl(&sch->schib.scsw) & SCSW_ACTL_HALT_PEND) && + !(scsw_actl(&sch->schib.scsw) & SCSW_ACTL_CLEAR_PEND)) { + if (!scsw_is_tm(&sch->schib.scsw)) { + ret = cio_cancel(sch); + if (ret != -EINVAL) + return ret; + } + /* + * Cancel io unsuccessful or not applicable (transport mode). + * Continue with asynchronous instructions. + */ + *iretry = 3; /* 3 halt retries. */ + } + /* Stage 2: halt io. */ + if (!(scsw_actl(&sch->schib.scsw) & SCSW_ACTL_CLEAR_PEND)) { + if (*iretry) { + *iretry -= 1; + ret = cio_halt(sch); + if (ret != -EBUSY) + return (ret == 0) ? -EBUSY : ret; + } + /* Halt io unsuccessful. */ + *iretry = 255; /* 255 clear retries. */ + } + /* Stage 3: clear io. */ + if (*iretry) { + *iretry -= 1; + ret = cio_clear(sch); + return (ret == 0) ? -EBUSY : ret; + } + /* Function was unsuccessful */ + return -EIO; +} static void cio_apply_config(struct subchannel *sch, struct schib *schib) { -- cgit v1.2.3